From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Responding to a query on the indicator diagram apparatus, detailing valve design, relief valve placement, and oil pump configuration.
| Identifier | ExFiles\Box 79\3\ scan0012 | |
| Date | 31th March 1917 | |
| To EFC. from E.{Mr Elliott - Chief Engineer} ? E2/B31.3.17. RE X.2981 - INDICATOR DIAGRAM APPARATUS. With reference to your memo EFC1/T27317, I deal with the points in the order in which you have mentioned them. Mr. Royce prefers the staggered valve, because the plug does not open up unnecessarily either to the gauge or to the engine cylinder, as does the first one illustrated. Even if we used the last named, I think we should make the ports normal as in the sketch, and not straight through. Since we are building up the pressure by increments from one point in a cycle which is generally very constant in its behaviour, the question of damping should not enter into it, especially as the oil itself will give us a large damping effect. The relief valve should be placed in the position indicated by Mr. Royce, whose intention is that it shall blow off into the open air, for the sake of simplicity. The air vessel is intended to neutralise the impulses of the oil pump and give a steady reading on the gauges. For this purpose it is important to connect it up so that there is no restriction in between it and the gauges, thus :- [Hand-drawn diagram of a line connecting GAUGES and PUMP] GAUGES PUMP The oil pump is intended to run at a speed which will [Footer text, upside down]: R.R.A 236 (400 T) (S. C) 536. 15-2-10 (G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1548). | ||